Adjusting gains and HU Pre-Out Volts

[Ken448 10+ year member]

When adjusting gains using a DMM, does the headunits preout voltage have anything at all to do with the equation? I adjusted by ear, and checked with a DMM, and I was a bit high on the voltage reading, but I had no AUDIBLE distortion when playing some acoustic music (Hotel California) and sounded clean playing Nickleback as well.

Thing is, my amp is supposed to put out 85X2 @2 ohms, and 420X1 @2ohms (Kicker zx550.3) but the "birthsheet" says its total of 788 watts. However, I dont beleive the birthsheet is anything but a random computer generated peice of paper with my amps serial number stuck on it. They certainly arent like the old school hand written birthsheets.

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[ProgMtl 10+ year member]

Most HU's won't put out they're prescribed voltage (whether it be 2, 4, 5 or 8 volts...or whatever) without the subwoofer setting being all the way up...an also the volume near the clipping point (checked my old Premier P780-MP with an oscope and it wasn't putting out 4 volts until I was at 58/62 on the volume knob...didn't clip until 61/62 though).

What HU do you have? I'm sure someone on here has tested the same brand to see where it starts to clip on the volume knob....most Premier's I've heard about clip at 61/62 and alot of the Alpine's clip at 32/35.

Now if you're just asking about whether 2 volt or 4 volt preouts make a difference when using a DMM the answer is no...just set it where your equation tells you to.